← Back to Skills Marketplace
271
Downloads
1
Stars
1
Active Installs
1
Versions
Install in OpenClaw
/install crontab-wizard
Description
Explain, generate, validate, and preview crontab expressions. Use when a user needs to understand what a cron expression means, create a new cron schedule, c...
README (SKILL.md)
Crontab Wizard
Decode, generate, validate, and preview cron schedules from the command line. Zero dependencies.
Quick Start
# Explain what a cron expression does
python3 scripts/cronwiz.py explain "*/5 * * * *"
# Generate an expression from options
python3 scripts/cronwiz.py generate --every 5m
# Check if an expression is valid
python3 scripts/cronwiz.py validate "0 9 * * 1-5"
# See when it runs next
python3 scripts/cronwiz.py next "0 9 * * 1-5" --count 10
Commands
explain — Decode cron to plain English
python3 scripts/cronwiz.py explain "30 2 * * 0"
# → At 02:30, on Sunday
python3 scripts/cronwiz.py explain "@daily"
# → At 00:00
python3 scripts/cronwiz.py explain "0 */6 * * *"
# → At minute 0, every 6 hours
validate — Check for errors
python3 scripts/cronwiz.py validate "0 9 * * 1-5"
# → VALID: 0 9 * * 1-5
python3 scripts/cronwiz.py validate "0 25 * * *"
# → INVALID: hour: 25 out of range (0-23)
next — Preview upcoming runs
python3 scripts/cronwiz.py next "0 9 * * 1-5" --count 5
# Shows next 5 weekday 9 AM runs with dates
generate — Build expressions from options
python3 scripts/cronwiz.py generate --every 5m
# → */5 * * * *
python3 scripts/cronwiz.py generate --every daily --at 09:00
# → 0 9 * * *
python3 scripts/cronwiz.py generate --every week --at 14:30 --on friday
# → 30 14 * * 5
Generate options
| Flag | Values | Description |
|---|---|---|
--every |
5m, 2h, daily, weekly, monthly |
Interval |
--at |
HH:MM |
Time of day |
--on |
mon–sun, weekdays, weekends |
Day of week |
Supported Shortcuts
@yearly, @annually, @monthly, @weekly, @daily, @midnight, @hourly
Dependencies
None — pure Python, no pip installs required.
Usage Guidance
This skill appears coherent and self-contained: it runs a local Python script to parse and preview cron expressions and does not request credentials or network access. Before installing, confirm you are comfortable running third-party Python scripts in your environment (review the full script if you want to check for bugs or style issues). If you plan to run it in automated or high-privilege contexts, consider running in an isolated environment (virtualenv or container).
Capability Analysis
Type: OpenClaw Skill
Name: crontab-wizard
Version: 1.0.0
The crontab-wizard skill is a utility for explaining, validating, and generating cron expressions. The implementation in `scripts/cronwiz.py` is written in pure Python using standard libraries (argparse, datetime, re) and contains no network calls, file system modifications, or shell execution logic. It functions strictly as a string parser and date calculator, with safety limits in the `next_runs` function to prevent infinite loops.
Capability Assessment
Purpose & Capability
The name and description (crontab parsing/generation/preview) align with the included Python script and SKILL.md examples. There are no unrelated environment variables, binaries, or external services declared or required.
Instruction Scope
SKILL.md explicitly instructs running the bundled Python script with local arguments (explain/generate/validate/next). The instructions do not ask the agent to read arbitrary files, access credentials, or send data to external endpoints; the script operates on provided cron expressions and local time only.
Install Mechanism
No install spec is provided and the skill is instruction-only plus a local Python script. Nothing is downloaded or written to disk by an installer step—lowest-risk install posture.
Credentials
The skill declares no required environment variables, credentials, or config paths. The code excerpt shows no access to environment secrets or external services, so requested privileges are proportional to the stated functionality.
Persistence & Privilege
always is false and the skill does not request persistent or elevated agent-wide privileges. There are no indications it modifies other skills or agent configuration.
How to Use
- Make sure OpenClaw is installed (local or Docker)
- Run the install command in chat:
/install crontab-wizard - After installation, invoke the skill by name or use
/crontab-wizard - Provide required inputs per the skill's parameter spec and get structured output
Version History
v1.0.0
Initial release of crontab-wizard.
- Explain cron expressions in plain English, including shortcuts like @daily and @hourly.
- Generate cron expressions from simple options (intervals, time, days).
- Validate cron expressions, highlighting errors if present.
- Preview upcoming run times for any cron schedule.
- Supports standard 5-field syntax and common shortcuts.
- No dependencies; runs with standard Python.
Metadata
Frequently Asked Questions
What is Crontab Wizard?
Explain, generate, validate, and preview crontab expressions. Use when a user needs to understand what a cron expression means, create a new cron schedule, c... It is an AI Agent Skill for Claude Code / OpenClaw, with 271 downloads so far.
How do I install Crontab Wizard?
Run "/install crontab-wizard" in the OpenClaw or Claude Code chat to install it in one step — no extra setup required.
Is Crontab Wizard free?
Yes, Crontab Wizard is completely free, licensed under MIT-0. You can download, install and use it at no cost.
Which platforms does Crontab Wizard support?
Crontab Wizard is cross-platform and runs anywhere OpenClaw / Claude Code is available (cross-platform).
Who created Crontab Wizard?
It is built and maintained by John Wang (@johnnywang2001); the current version is v1.0.0.
More Skills